package demo1;

/**
 * Definition for singly-linked list.
 * class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode(int x) {
 *         val = x;
 *         next = null;
 *     }
 * }
 */
public class Solution {
    public boolean hasCycle(ListNode head) {
         ListNode slow = head ;
         ListNode fast = head ;
        while(fast!=null && fast.next!= null){
            slow = slow.next ;
            fast = fast.next.next ;
            if(fast == slow){
                return true ;
            }
        }
           return false ;

    }
}
/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode(int x) {
 *         val = x;
 *         next = null;
 *     }
 * }
 */
